Fourteen years ago, Steve Martin, Chevy Chase and Martin Short appeared in a clever, funny, heavily promoted film that performed dismally at the box-office. The Three Amigos was the tale of three unemployed silent film stars who had long specialised in playing virtuous Mexican cowboys sporting garish costumes and big hats. But their time had come and gone, and now they were looking for work. Any kind of work. One day, the amigos receive a tersely worded telegram from a tiny Mexican village requesting that they trundle down and help rid the peasants of their oppressor, the dreaded bandito "El Guapo". The compadres naturally assume that they have been invited south of the border to put on a show and regale the entertainment-starved paeons with their winning antics. So off they go. Alas, they soon discover that El Guapo is a genuine murderer, that the peasants are truly expecting salvation, and that the imbroglio they have entered involves real guns and real bullets. So they decide to run away.

But then, much like the gunslingers with hearts of gold in The Magnificent Seven, the film that The Three Amigos ingeniously parodies, Martin, Chase and Short rise to the occasion and defeat El Guapo, thereby attaining a heroic stature they have heretofore only simulated. Yet despite this original plot, hilarious musical production numbers, crackling dialogue, wonderful work by Martin and Short, and a surprisingly animated performance from the usually AWOL Chase, The Three Amigos was a bomb. Were those of us who adored this cheerfully inane film completely out of our minds? Or was The Three Amigos a film that was ahead of its time?

To make a long story short, The Three Amigos was simply a film that was ahead of its time. But now that it has been re-released as Galaxy Quest, those who missed it the first time around can atone for this oversight. In Galaxy Quest, Tim Allen, Sigourney Weaver and Alan Rickman play pathetic, ageing veterans of a TV show not unlike Star Trek that was cancelled a generation ago, not unlike Star Trek, but has since spawned a huge cult following, not unlike Star Trek. To keep their creditors at bay, the trio of hams, accompanied by several even less glamorous chums, must make an endless series of personal appearances at conventions, department store-openings, etc. They are tragic little has-beens, and they despise one another. Whether this accurately describes the relationship between the survivors of Star Trek, I have no way of knowing. But I would certainly hope so.

One day, Allen hooks up with a quartet of star-struck space bozos who escort him to what he believes is yet another promotional appearance. In fact, the four visitors are genuine extraterrestrials who have seen Allen's antics on TV but who have no way of knowing that his mighty deeds are fake. The space dorks, who bear a definite facial resemblance to the Teletubbies, want Allen and his crew to venture deep into space and rescue them from a cruel, voluble reptile who seems determined to reduce their civilisation to rubble.It takes Allen quite a long time to realise what is happening here, and his crew members are not much faster on the uptake. But eventually, having taken a genuine liking to their hosts, they realise what is expected of them and rise to the occasion. They rise to the occasion the way Toshiro Mifune did in the Seven Samurai, and the way Yul Bryner did in The Magnificent Seven, and the way Steve Martin and Martin Short and Chevy Chase did in The Three Amigos, because these are all the same movie.

People who dislike the tomfoolery Star Trek has unleashed on society should not be put off by the forgoing paragraphs. When I first asked my 13-year-old son if he would like to see Galaxy Quest, he asked me what kind of a jerk I thought he was, since wholesome teenage boys loathe Star Trek, and have occasionally been known to put overbearing Trekkies to the sword. But when I assured my son that Galaxy Quest would be a merciless attack on the Star Trek cult - and here I was only guessing - he finally agreed to attend. To our relief, we found that most of the people in the audience would never be mistaken for Star Trek aficionados, because they were normal, good-looking, suitably attired, and in some cases, female - a gender never seen at any Star Trek convention I know of. And, yes, a good time was had by all, since what is bad for Trekkies - movies like Galaxy Quest - is good for humans.

A few caveats. Until I saw Galaxy Quest, I had not been a big fan of Tim Allen as a movie star. Reliably amusing as the tool guy on TV's Home Improvement, Allen seemed to phone in his performances in films such as The Santa Clause. But perhaps because Galaxy Quest is about an ageing star of the tiny screen who is suddenly asked to perform truly heroic feats, Allen seemed perfect for the role of William Shatner/Captain Kirk, pompous ass. Meanwhile, Alan Rickman, who seems like a strange chap anyway, was impeccably cast in the role of the drab, emotionless Doctor Spock.

But the biggest surprise of all was Sigourney Weaver, in an uncharacteristically voluptuous performance as Allen's gorgeous, pointless Space Sidekick. It's been years since Weaver appeared in anything that was even vaguely funny, and Galaxy Quest affords her a brief respite from her official role as the Baby Boomer Joan Crawford. It cannot be an accident that Weaver, obstreperously bald in Alien III, herein sports the most bellicose wig since Mary-Elizabeth Mastrantonio donned that Pam Grier Afro in Scarface. No, it is not an accident; it is, in fact, one of the best jokes in a very funny film. Not as funny as The Three Amigos, of course. But then again, what is?